Light and load brake apparatus.



R. A. PARKE.

LIGHT AND LOAD BRAKE APPARATUS.

APPLICATION FILED SEPT. 2, 190s.

1,025,297. Patented My 7,1912.

COLUMBIA PLANOGRAPH cu.. WASHINGTON. u. c

UNITED STATES PATENT OFFICE.

ROBERT A. PARKE, 0F PARKE MINES, ONTARIO, CANADA, ASSIGNOR TO THEWESTING- HOUSE AIR BRAKE COMPANY, OF PITTSBURGH, PENNSYLVANIA, ACORPORATION OF PENNSYLVANIA.

LIGHT AND LOAD BRAKE APPARATUS.

To all whom it may concern:

Be it known that I, ROBERT A. PARKE, a citizen of the United States,residing at Parke Mines, in the district of Nipissing, Province ofOntario, Dominion o-f Canada, have invented new and useful Improvementsin Light and Load Brake Apparatus, of which the following is aspecification.

This invention relates to light and load brake apparatus and has for itsobject to provide improved means for effecting a different and greaterretarding friction of the brakes upon the car wheels, more particularlyof freight cars, when the cars are loadedl than when they are notloaded. When the cars are loaded, the momentum of the added weight hasalso to be stopped by the air brakes, and the distance in which thetrain can be stopped increases directly in proportion with the increasedtotal weight of the train. The recent practice of building cars of veryhigh carrying capacity has increased the relative weight of the train,when loaded, to such an extent that the stopping distance is from fourto five times as great as when the train is not loaded, and it hasbecome very important to provide an increased stopping capacity of thebrakes of loaded freight trains, not only for reasonable protectionagainst accident to themselves and other trains, but also for thesatisfactory operation of such trains in ordinary service.

To accomplish this purpose, my invention consists in the combination ofcertain novel devices, hereinafter set forth, whereby the air pressurein the brake cylinder upon each car shall be so controlled that, as atpresent, it shall have a moderate limit in all service application ofthe brakes, and be increased to the proper limit in emergencyapplications, when the car is not loaded, and it shall have a similardifference of service and emergency application limits, of much greaterdegree, when the car contains more than a certain fixed load.

It includes the use of a novel form of pressure regulating valve,introduced in the freight car apparatus of the ordinary quick action airbrake between the auxiliary reservoir and the brake cylinder, wherebythe proper pressures are provided through the aid of a pawl or latchwhich is ope-rated by means of a simple mechanism attached tospecification of Letters Patent.

Application filed September 2, 1909.

Patented May '7, 1912. Serial No. 515,896.

the car body and so connected to one of the trucks that it is actuatedby the downward movement of the car body, in the yielding of thesprings, when the car is loaded. When the load exceeds a fixed amountthe mechanism is thus actuated to move the pawl in the pressureregulating valve, by which the higher service and emergency brakecylinder pressure become available.

This device is wholly different from those which seek to regulate theforce of the brakes according to the load. It is well known that thesprings in the trucks which are adapted to the intended loading of thecar, gradually settle downward through the vertical distance allowed forthe purpose, as the car is loaded. This downward movement isproportional to the load placed in the car, until the entire loadcompletes it. It has been proposed to utilize this condition, throughvarious devices and means, to cause the force with which the brakes areapplied to the car, to vary in proportion to the load upon the springs.Means have been employed to cause the force of application to varybetween fixed -limits by the immediate influence of the depression ofthe springs by the load. Others have provided for indirectly utilizingthe principle through introducing into the brake system upon the car alever adapted to lift the car body from the center plate, the resultingmovement of which expanded the air in the brake cylinder and so limitedthe air pressure. yIn each case it is the purpose to provide a variableresisting power of the brakes, which is to be measured by the weight ofthe load in the car. My purpose, on the contrary, is to provide theusual braking resistance for the unloaded car and, in addition, acertain greater braking resistance, to be used only when the load in thecar exceeds a corresponding weight; and the vertical movement of the carbody, resulting from deflection of the springs by the load,automatically operates to both determine the proper load and actuate themechanism which provides the corresponding air pressures in the brakecylinder.

In the accompanying drawing, which illustrates one form o-f apparatusembodying my invention, Figure l is a sectional view of a portion of theunderframing and a truck of a freight car with the air brake apparatusshown in side elevation; Fig. 2 is a longitudinal sectional vieW of theimproved pressure controlling valve; and Fig. 3 is a modified form ofthe apparatus for actuatingthe operation of the pressure controllingvalve.

In Fig. 1 is shown the apparatus of a form of the ordinary quick actionfreight car brake, including branch pipe 1 leading from the train pipeto the triple valve 2,

which is secured directly to the auxiliary reservoir 3. Pipe 4ordinarily leads directly from the triple valve (through the auxiliaryreservoir) to the brake cylinder, but Wit-h my invention it leads toaressure controlling valve 5, from which` pipe 6 leads to the brakecylinder 6 Which in this form of the brake apparatus is located directlyback of the auxiliary reservoir 3. In addition to the ordinary apparatuspipe 7 leads from the triple valve to the pressure controlling valve 5.Extending outward and upward from the pressure controlling valve 5 thelever 8 is pinned at its upper end to connecting rod 9, the other end ofwhich is connected to the disk 10, supported from the car body by frame11 in such a manner that disk 10 is free to rotate upon a central pinextending through frame 11. Upon an arm extending radially outwardlyfrom disk 10 in the direction of connecting pin 21 from the center ofthe disk is a Weight 20, and the rotation of disk 10 is limited, throughthe pinned connection of the rod 9, by the movement of the upper end ofthe lever 8 of the pressure controlling valve. The radial direction ofthe pin 21 and Weight 2O is such that the Weight 20 is about equallydistant from the vertical line through the center of rotation of thedisk When the lever 8 is at opposite ends of its movement. Similarlysecured by a cylindrical pin at the other end of frame 11 is a lever 12,one end of Which is secured by a pin to the connection 13, which is alsosecured by pin tothe bracket 14, which is bolted to the channel 15,Which forms the spring plank of the truck. The other end of lever 12moves freely in the guides 1G, formed integrally with frame 11, theextreme end being rounded to a small semicircle, and for a distance fromthe end, equal to the radius of disk 10, the edges have curved faces toengage the cam-like faces of the disk 10 with which they come intocontact. The disk 10 is directly in the path of the end of lever 12, thecenter of the disk lying just beyond the circular path of the end of thelever, and the disk is cut away and the edges of the remaining portionare formed in such a manner that the lever does not come into contactWith the disk until just before it reaches the horizontal position, andjust after passing the horizontal position the disk has been moved sothat the position of the Weight 20 operates to continue and complete themovement by gravity, practically independently of lever 12, to theopposite position indicated in dotted lines.

Thatever the load designed to be carried, the springs are soproportioned that only about one and one-half inches depression resultsfrom the load. To nicely determine the load which has been selected asthe loaded weight for increased braking ellieiency, Whether all orWhatever portion of the full Weight of the load, and to assure theopera.- tion of the increased brake cylinder pressures with a loadvariation Within reasonable limits, Where the car is partially loaded,the operative movement of the Spring depression is multiplied by the useof the lever 12, which, being as one to four, has a total movement ofabout 6 inches at the end operating the disk. It is then placed in sucha position, in securing frame 11 to the car frame, that the roadselected for increased braking power shall bring the lever into ahorizontal position. The edges, acting as cams, of the disk illustratingmy invention, are straight, terminating at the center vvi th a circularcurve of the same radius as that of the semicircular end of the lever,and the slight circular curvature of the edges of the lever Where theymust meet the straight edges of the disk result in the maximum leverageupon the disk at the beginning of the movement when the resistance ofthe weight is the greatest, and in the minimum resistance to themovement of the disk when its movement is the most rapid, at the timewhen the lever operates with the least advantage. Thus, as the weight ofthe disk is slight and the Work of the operation is triliing, thefriction and Wear are minimized and are very small.

While the operation of loading and unloading a car is comparativelyinfrequent, so that the Wear upon such an apparatus from operation issmall, the constant vi bration of an apparatus, moving with everydeflection of the springs of a car in service, becomes a very differentconsideration. It is the freedom of the disk and all the parts connectedwith it from further influence by lever 12, operatively moved intoposition, that com prises one of the advantageous features of theapparatus. The depression of the springs by t-he load promptly andeffectively introduces the higher brake cylinder pressures, under theproper conditions, and vice versa, While the Wear and disorder of theapparatus that must result from the constant vibration that mustaccompany the continued influence of the spring action, are Whollyavoided.

In the operation of the air pressures the air from the auxiliaryreservoir is conducted to the brake cylinder in all service applicationsof the brakes through pipe 7, Which en- ICO after it has once been tersthe pressure controlling valve through the connection 22, shown indotted lines in Fig. 2, and thence through the annular passage 23 andport 24 into the valve chamber 25.

In my application, Serial No. 515,895, iiled Sept. 2, 1909, forimprovement in high speed brake apparatus, I have fully described theconstruction of the triple valve by which the auxiliary reservoir airpressure can have access to the brake cylinder by no other means, exceptin emergency applications of the brakes. The same construction may alsobe employed in the triple valve ot the appa natus used in the practiceot' my present invention.

The pressure controlling valve, as shown in Fig. 2, consists of acasing, in four sections, the upper one of which 26 contains bushings 27and 28. In the latter, piston 29 is secured to stem 30 and operatesslide valve 31 which is located between the collars 32 and 33 upon stem30. Beside port 24, slide valve 31 also controls the double port 34 inbushing 27, the port 34 being divided, and the slide valve 31 beingprovided with two corresponding openings to reduce the valve travelotherwise necessary. In emergency applications of the brakes the airfrom both the train pipe and auxiliary reservoir enters valve chamber 25through pipe 4, and in all cases the air passes through ports 34 andpipe 6 to enter the brake cylinder. The lower end of piston stem 30rests upon the cylindrical abutment 35, which is supported by spring 3G,the latter being adjusted and held in place by adjusting screw 37 whichis then secured by nut 38. Abutment 35 is free to move downward in thecylindrical ring 39, which incluses and guides it until the flange atthe upper end ot' abutment 35 meets the shoulder produced by the bottomot the annular recess in the upper end of ring 39 provided for the freemovement of the flange. Ring 39 is supported by spring 40, which isadjusted and held in position by the adjusting nut 41, which is in turnlocked by the third section of the casing 42. A rod 43 extends looselythrough adjusting screw 37 and is secured to abutment 35 by screwinginto the central boss which extends downward through the interior ofspring 36 and is locked in place by lock nut 44. The fourth section 45of the casing incluses the lower end of the device by screwing intosection 42 and is locked in place by lock nut 48. The lower end of lever8 passes through a slot in cap 45, to which it is secured by pin 46. Thelever terminates in a pawl or latch 47 having a cylindrical faceconcentric with pin 46. When springs 3G and 40 have been adjusted theadjustment of rod 43 and cap 45 are such that the outward movement otlever 8 brings pawl 47 immediately below the lower end of rod 43, sothat no downward movement of the rod or of the abutment 35 can takeplace, and thereby locks the valve mechanism in its normal open p0-sit-ion.

The operation of the apparatus is as tollows: Zhen the car is not loadedthe posit-ion ot thel disk 10 and of lever 8 remains as shown in thedrawings, and abutment 35 is tree to be moved downward by piston 29 whenthe air pressure upon it exceeds the resist-ance of spring 36. Inservice applications ot the brakes the air from the auxiliary reservoirpasses to the brake cylinder by the pipe 7 and enters the pressurecontrolling valve through portI 24, from which it passes through ports34 and pipe 6 to the brake cylinder. Spring 36 is so adjusted that whenthe prescribed limit of brake cylinder pressure for service applicationsupon unloaded cars is reached, that pressure moves piston 29 downward,causing slide valve 31 to close port 24 and thereby prevent any greaterpressure in the brake cylinder. til the flange of abutment 35 isarrested by the shoulder of ring 39 where the resistance of spring 40also opposes further movement of the piston. In emergency application ofthe brakes the brake cylinder pressure is about 2O per cent. greaterthan in service applications, and spring' 40 is so adjusted that thecombined resistance of springs 36 and 40 requires about 20 per cent.greater air pressure upon the piston 29 to move the valve 31 down toclose the ports 34 than is required to close port 24. Therefore when anemergency application is made the air under pressure, which then flowsfrom the triple valve directly through port or pipe 4 to the chamber 25,accumulates upon the piston 29 to a degree suficient to move the samedownward to compress both springs 36 and 40 and close the ports 34 tocut oit further supply to the brake cylinder.

When the car is loaded the disk 10 is moved into the position shown indot-ted lines Fig. 1, and lever 3 is moved outward so that pawl 47prevents any movement of piston 29 of valve 31. In this condition theair passes through the controlling valve without being infiuenced, andthe full brake cylinder pressure in service applicationsI will be thatof equalization with the pressure of expanded auxiliary reservoir air.In the emergency application the brake cylinder pressure will ot' courseexceed that of full service application by the added pressure of airreceived directly from the train pipe. The pressure cont-rolling valvethus becomes actively operative only when the car is unloaded, and it isthen operative in limiting the brake cylinder pressure in both serviceand emergency applications oi they brakes. In emergency applications itis important that an unobstructed passage of The piston moves downwarduncomparatively large area shall lead from the triple valve to the brakecylinder, for rapid release or' th-e train pipe air is essential to thequick serial action of the brakes through the train. Even by dividingport 34, and thereby reducing the required valve travel, the necessaryarea of port 34 still requires a comparatively long movement of thevalve to close it. i short movement closes port 29, and a pressure about2O per cent. greater must occur before port S4 is closed, while it isessent-ial that port 34 shall remain fully open until it closes, and notgradually close, as the pressure increases. No single spring couldprovide the necessary resistances for the required operation withoutdiiiicult or undesirable construction and much useless valve movement.By the use of two springs each contains the least actual weight ofmaterial required for strength, the operations are distinct, prompt andcharacterized by the minimum difference of air pressures in the valvetravel of port closure. The valve movements are separate and distinctand nothing about either operates to prejudice or complicate theconditions or results of the other.

y A modiication of the apparatus that actuates the operation of thepressure controlling valve is shown in Fig. 3. The lever 12 is connectedto the spring plank of the truck by the connection 13, as in Fig. 1, butinstead of being fulcrumed by pin to frame 11 it is pinned to a plungerrod 51 which works vertically in the central cavity 52 oit cylinder 53,which is connected by pin at its upper end to the bracket 54 by which itis secured to the car frame. Rod 51 also works through a spring abutment55, at the lower end 0'1" the cylinder 53, which is secured in thecylinder, against the pressure ot spring 56, by the screw cap 57. Rod 51moves in pocket 52 through the whole movement of the deflection of thetruck springs, but when the deflection corresponds with the weight ofload chosen for loaded car braking, a shoulder on rod 51 engagesabutment 55, and further upward movement of the rod is aecompanied bythe abutment with corresponding compression of the spring 5G. The otherend of lever 12 is pinned to lever 49, which is secured by a pinconnection to frame 11 in a similar manner to that ot disk 10 in Fig. 1.Rod 9 is secured to lever 49 by pin 21, and the lower end oit lever 49is provided with a weight 50. lWhen the car is not loaded weight 50holds lever 49, with its attachcd parts, in the position shown in Fig.3, and lever 8 of the pressure controlling valve is in the positionshown in Fig. 1, so that the brake cylinder pressures are confined tothe interior limits of the unloaded car. When the car is loaded theconsequent depression or" the springs causes the relative movementupward of rod 51 in cylinder o3 until the shoulder thereof engagesabutment 55. Weight 50 is not sutlicient to resist the tension of spring5G, and further movement of lever 12 rotates lever 49, thereby movinglever 8 and pawl 47 of the pressure controlling valve, so that allmovement of piston 29 and valve 31 is cut oit. Thereafter, continueddepression of the car springs causes rod 51 to resume travel intocylinder 53, but accompanied by abutment 55 and correspondingcompression of spring 56, maintaining lever 49 and connected parts intheir acquired positions until removal of the load in the car allowsabutment 55 to bc returned to its seat by the spring 56, and lever 49and connected parts to be then restored to their positions in Fig. 3 byweight 50.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is

1. In a light and load brake apparatus, the combination with a devicefor limiting the Huid pressure in the brake cylinder when the brakes areapplied, of means controlled by the weight of the load tor cutting saiddevice into or out of operation.

2. In a light and load brake apparatus, the combination with a devicefor limiting the degree of iiuid pressure in the brake cylinder when thebrakes are applied, of a mechanism for cutting said device into or outoit operation, and means operated by the weight of the load foractuating said mechanism to either position.

8. 1n a light and load brake apparatus, the combination with a devicefor limiting the degree of fluid pressure in the brake cylinder when thebrakes are applied, of a mechanism for cutting said device into or outof operation, and means operated by the rise or fall of the car upon itssprings for actuating said mechanism to its respective positions.

4. 1n a light and load brake apparatus, the combination with a devicefor limiting the pressure with which the brakes are applied, of ashifting weight for cutting said device into or out of operation, andmeans operated by the weight of the load for shitting said weight to oneor the other position.

5. In a light and load brake apparatus, the combination with a valvedevice for normally limiting the pressure with which the brakes areapplied in service applications, ot means operated by the weight of theload for cutting said valve device into or out ot effective operation.

6. In a light and load brake apparatus the combination with a valvedevice for limiting the braking pressure in service applications to acertain amount and in emergency applications to a predeterminedditterent amount, of means for cutting said valve device into or out ofoperation.

7. In a light and load brake apparatus,

the combination With a train pipe, auxiliary reservoir, triple valve andbrake cylinder, of a controlling valve mechanism in the service portfrom the triple valve to the brake cylinder, and also in the emergencypassage from the triple valve to the brake cylinder.

8. In a light and load brake apparatus, the combination with a trainpipe, auxiliary reservoir, triple valve and brake cylinder, of acontrolling valve mechanism in the service port from the triple valve tothe brake cylinder, and also in the emergency passage from the triplevalve to the brake cylinder, and means for cutting said mechanism intoor out of operation.

9. In a light and load brake apparatus, the combination With a trainpipe, auxiliary reservoir, triple valve and brake cylinder, of apressure controlling valve mechanism having separate connections to thetriple valve service port, the triple valve emergency port and the brakecylinder.

10. In a light and load brake apparatus, the combination With a trainpipe, auxiliary reservoir, triple valve and brake cylinder, of apressure controlling valve mechanism having separate connections to thetriple valve service port, the triple valve emergency port and the brakecylinder, and means operated by diii'erent degrees of brake cylinderpressure for closing communication through the respective passages.

11. A controlling valve mechanism for brake cylinders, comprising apiston or abutment subject to brake cylinder pressure, a valve operatedby said abutment for controlling communication from the triple valveservice port and from the triple valveemergency portI to the brakecylinder, a spring acting to oppose the movement of the piston and valveto close the service communication and a second spring act-ing to opposefurther movement to close the emergency communication.

12. A controlling valve mechanism, comprising a piston subject to theopposing pressures of the brake cylinder and an adjustable spring forcontrolling communication from the triple valve service port to thebrake cylinder, and a second spring acting on the piston When theservice communication is closed to oppose the further movement of thesame in controlling the communication from the triple valve emergencyport to the brake cylinder.

13. A controlling valve device having ports adapted to communicate vviththe triple valve service port, the triple valve emergency port, and thebrake cylinder, a pisto-n subject to brake cylinder pressure, valvemeans actuated thereby for controlling said ports, a spring acting tooppose the preliminary movement of the valve, and a second spring actingto oppose the further movement thereof.

14. In a light and load brake apparatus, the combination of acontrolling valve device communicating vvith the brake cylinder landWith the triple valve service and emergency ports, and having a pistonand valve for controlling said communication, a spring opposing thepreliminary movement of the piston for governing the servicecommunication, a secondspring acting` to oppose the further movement ofthe piston for governing the emergency communication. and means forlocking said valve in its normal open position.

15. A controlling valve device having separate ports adapted to beconnected to the triple valve service port and triple valve emergencypassage respectively, and a piston and valve mechanism for controllingsaid ports and operated by one degree of brake cylinder pressure toclose communication from the service passage to the brake cylinder, andby a higher degree of pressure to close communication from the emergencypassage to the brake cylinder.

16. In a light and load brake apparatus, the combination with a devicefor limiting the pressure with which the brakes are applied, of meansfor cutting said device into or out of effective operation, andmechanism operated by the Weight of the load for shifting said cuttingout means at a certain point in its movement, but having free play uponboth sides of said point whereby the device is unaffected by the usualoscillating vibration.

In testimony whereof I have hereunto set my hand.

ROBERT A. IJARKE.

Witnesses J. S. DAVIS, E. A. WRIGHT.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents, Washington, 1). C.

